The FreeBSD implementation of Poul-Henning Kamp's timecounters
was ported and committed to NetBSD-current.

Timecounters will be supported on a per port basis. With
the commit following ports make use of timecounters:
    i386
    amd64
    sparc
    sparc64

Other ports will follow over the time. Hopefully all ports
of NetBSD will be converted to timecounters soon.

Benefits:
    - true nanosecond support
      within the limits of the hardware
    - easier interfacing to hardwarecounters as
      all scaling integration is done at MI level
    - new NTP API (Version 4) - aka Nanokernel
    - simplified internal interface for PPSAPI
    - MP support (minimal coordination needed)

Please test NetBSD-current so we can smoke out bugs early.

Further information:
    Timecounter Paper: http://phk.freebsd.dk/pubs/timecounter.pdf
    Current Status: http://www.kardel.name/timecounters-status.html
    NTP Nanokernel: http://www.eecis.udel.edu/~mills/ntp/html/kern.html

best regards,
  Frank Kardel & Simon Burge